Cylindrical battery

A cylindrical battery comprising:

• an electrode group;
• an electrolyte;
• a battery can that houses the electrode group and the electrolyte;
• and an opening sealing body that seals an opening of the battery can,
• the opening sealing body including a valve member, a metal plate disposed on an inner side of the battery with respect to the valve member, and an annular insulating member interposed between the valve member and the metal plate,
• wherein the valve member and the metal plate are connected to each other at respective central portions, the valve member has an annular thin-walled portion which is deformable when an internal pressure of the battery increases,
• the metal plate and the insulating member have respective holes which communicate with each other, wherein a plurality of the holes of the metal plate and a plurality of the holes of the insulating member are provided,
• the insulating member has a section P1 that covers a surface, on the valve member side, of the metal plate, and a section P2 that is provided adjacent to the section P1 and covers an inner lateral surface of the holes of the metal plate, wherein a proportion of lateral sides, covered by the section P2, of the holes of the metal plate is from 20% to 90%, and
• wherein the insulating member has a section P3 that is extended from the section P2 and covers a surface of the metal plate, said surface of the metal plate facing toward the electrode group in a thickness direction of the metal plate.